Regensburg 2000 – wissenschaftliches Programm

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DY: Dynamik und Statistische Physik

DY 20: Struktur und Chaos

DY 20.2: Hauptvortrag

Dienstag, 28. März 2000, 10:00–10:30, H2

Patterns, Structure and Correlations in Granular Fluids — •Matthieu H. Ernst — Universiteit Utrecht,NL

To analyze the patterns and to describe the structure and correlations in the density and flow field of dissipative granular fluids we develope a Cahn-Hilliard type theory. Two different mechanisms for pattern formation are identified: a spinodal decomposition-type mechanism for the formation of density clusters, and a mechanism for selective noise reduction that leads to vortex formation, called "peneplanation". This theory gives a quantitative description of structure functions and spatial and temporal correlations, among which algebraic tails, that are absent in elastic fluids. The theory is compared with molecular dynamics simulations.